


warp of water, weft of stone

by jediseagull



Category: Rivers of London - Ben Aaronovitch
Genre: (kind of), Case Fic, Dark with a happy ending, M/M, cosmic horror
Language: English
Status: Completed
Published: 2017-12-18
Updated: 2017-12-18
Packaged: 2019-02-16 11:47:08
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 10,776
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13053384
Author URL: https://archiveofourown.org/users/jediseagull/pseuds/jediseagull
Summary: The demi-monde is at peace.Thomas Nightingale, however, is not.





	warp of water, weft of stone

**Author's Note:**

  * For [Bond_Girl](https://archiveofourown.org/users/Bond_Girl/gifts).



> Happy holidays, Bond_Girl! I hope you enjoy this slightly morbid romp through magical Britain. 
> 
> Huge thanks to plalligator, perennial Yuletide Hero, for helping me jump-start this idea, and to my friends and family, for putting up with two months of complaining about the words Not Happening. For more fic (and, realistically, more grumbling about fic), come say hi on [Tumblr](http://jedi-seagull.tumblr.com)!
> 
> Please note that this story contains shades of suicidal ideation; no characters actually contemplate or commit suicide, but it deals with some dark themes. If you're not sure how you feel about that, now is a good time to click away.

The trouble started the day Thomas went to see Varvara Sidorovna Tamonina. London had yielded to the changing of the seasons with its usual easy capitulation; on that Thursday in early October the radio weatherman had informed him the temperature would reach no higher than 13 degrees. It would, the weatherman warned, feel colder. A persistent drizzle had started falling over the city the previous morning and quite refused to leave. Outside Thomas’s window, the lawn of Russell Square was sodden, mud puddles forming where the grass had thinned.

It was the sort of day that demanded one wrap oneself in layers of good British wool before venturing outdoors, and when Thomas stepped to the armoire he found it had been rearranged accordingly. All his suits of linen and cotton had been covered in garment bags and moved to the back, and the heavier wools which had slowly been returning to regular use had been put into neat order at the fore. Molly possessed a near-supernatural sense – possibly in the most literal meaning – for the change in weather which heralded a wardrobe rotation. Thomas had long stopped being surprised that she would anticipate him, but he would never fail to be grateful for it.

The slate grey suit hanging conspicuously apart from the others, however, was less anticipation of his preferences than it was Molly’s pointed method of expressing her own. Where worsted wool might convey workmanlike anonymity, and tweed the old-fashioned charm of the countryside, flannel gave off an air of ruthless indifference. It was the suit choice of a man who dressed well not because he needed to impress others, but because he could.

Under that soft elegance, It was also a tough, durable fabric. He’d purchased his first grey flannel suit on Savile Row from the original Mr. Skinner’s son upon his return from the tropical climes of the colonies, when he’d no longer been accustomed to the bite of a London winter. Skinner’s grandson had taken over the running of the business before he’d had to replace it, and it might very well be the great-grandson from whom Thomas would purchase another.

The sartorial semaphore was promising. While Molly would never be happy about these occasional meetings with Varvara, Thomas thought she had at least resigned herself to his spending time with people who had tried to kill him and was content with insisting that he not let them succeed. A gentleman in a flannel suit did not start fights, but he could certainly finish them.

Peter, meanwhile, had taken the news that Thomas was still in contact with the Night Witch with his usual good humor. “I get it,” he’d said. “Velociraptor chomps scientist, t-rex chomps velociraptor, scientist realizes discretion is the better part of valor and sneaks away to do science elsewhere while t-rex is occupied with the crossword.” His eyes had narrowed speculatively. “We really need that remote temperature sensor. Where do you reckon a t-rex falls between paper target and Tiger tank in terms of susceptibility to fireballs?”

Over the years, Thomas had developed a keen sense for which of Peter’s rhetorical questions were not actually rhetorical, and an even keener sense – mostly out of self-preservation – for which signaled a potentially brilliant-but-unconventional innovation, and which meant impending chaos, combustion, and Peter poking his head up from the wreckage swearing up and down that he didn’t mean to vanish the Tower of London three hundred years into the past, _honest_.

Thomas had deemed this particular query acceptable to ignore. Peter’s last venture into the biological sciences had resulted in all junior members of the Folly being banned from Abdul’s workplace unless they were in possession of a dead body or about to become one themselves. While Thomas had no doubt that Peter could revive the dinosaurs if given sufficient motivation and the appropriate tools, he was unlikely to stoop to breaking and entering to accomplish it. 

And clearly, Peter had understood _why_ Thomas needed to do this. Meeting Varvara sent as much of a message as wearing a particular article of clothing did. The Folly’s image had changed for the better over the last decade, but the Nightingale remained a fixed point. If he was to be a steel-jawed trap, waiting for someone to step out of line, it was not because Varvara had tried to kill him. It was because she had tried to kill Peter.

He reached for the suit.

By the time Peter appeared downstairs at the breakfast table, Thomas had made significant headway into his full English and was contemplating whether another helping of buttered toast might stave off the sloshing sensation in his stomach. Having gotten her way about his wardrobe, Molly had been topping off his coffee with alarming enthusiasm.

“I just got a call from Guleed,” Peter said. He was wearing what Thomas thought of as his home jumper, an endearingly hideous creation patterned with purple, blue, and teal chevrons that he claimed was too comfortable to give away and too ugly to wear out of doors. In contrast to the soft drape of the knit, the angles of his face and shoulders seemed even sharper than usual. “Also, good morning, sir. Molly.”

“Good morning,” Thomas said, and took the opportunity to pour the rest of the coffee pot into a mug for Peter while he went to collect a plate. “It’s early for her to be working. What did she want?”

“Missing persons,” Peter said, sitting across from Thomas. He fell immediately upon his coffee without bothering to doctor it with cream and sugar, and Thomas sat up a little straighter. Missing persons cases were difficult at the best of times because the trail could go cold so quickly and because there weren’t always clear signs of ill intent. None of the Murder Investigation Teams, Belgravia included, would get anywhere near a case if they thought there was a good chance they would find their victim been vacationing in Majorca with her cabana boy the entire time. “She talked to Stephanopoulos and they’re both pretty sure it’s one of ours. Mr. Salman Davies, Mrs. Cynthia Wheeler, and Ms. Ngozi Okore, no apparent connection apart from the fact that in the last five weeks, all three of them bought train tickets to Knaresborough with no warning and then fell off the grid once they got there. Guleed had one of her minions do some digging and they’d all gone to the British Museum right before they vanished.”

“It certainly sounds like something unusual may be at play. They all reached Knaresborough station?”

Peter nodded. “Guleed uploaded the security footage to HOLMES, so I was going to review it this morning, then go by the museum after lunch, take a sniff around for any _vestigia_.”

“Very well. Other than the obvious, is there a particular urgency that has Belgravia getting involved before 8AM?”

“Fundraising gala tomorrow night,” Peter said.

“Ah,” Thomas said. “In that case, I may join you when I’ve finished with Ms. Tamonina.”

After Holloway had closed in 2016, the Night Witch had been moved an hour outside of London to HMP Downview. There had been some discussion as to whether she ought to go to Bronzefield instead owing to the higher security category, but Thomas had pointed out that she had been offered every opportunity for escape during the matter with the Russian gangsters several years prior; not only had she remained in custody, but she had been of considerable help in their investigation. Thankfully, he had not needed to add that should she genuinely make an escape attempt, the higher security would only mean a greater number of casualties. Downview it was.

There had been a great deal of fuss, too, over the Met’s insistence that Falcon matters not be tossed about willy-nilly on official record, countered by the prison’s equally stubborn insistence that Thomas could not simply meet with a female prisoner unsupervised and off the record. The agreement they had reached at Holloway, and which held at Downview, was that for the purpose of security there would be a monitored video feed but no audio recording. The guard who escorted Varvara to and from the private room would remain inside, though it was unclear whether she remained for his protection or for Varvara’s. None of the prison staff seemed to know either, which of course the Night Witch found hilarious.

“Thomas.”

“Varvara. I trust you’re well?” For a woman who’d attained her century last year, she looked it. She had been forty-five when the magic had changed her; she had never grown old as Thomas had. Her body remembered only the sharp lethality of her power at its apex, and incarceration hadn’t dulled its edge in the slightest.

“They’ve started offering vocational training here.” Her grin was quick and mirthful. “Did you know that? I’ve been learning how to build furniture. Maybe I’ll take up carpentry in my next lifetime.”

“A noble trade,” he acknowledged. “May I?”

“If you must.” Varvara stuck out her wrist and rolled her eyes at the female guard in the corner. “Thirty seconds of foreplay and he wants to jump straight to the good stuff. _Men_.” The guard remained blank-faced. Varvara sighed. “The new ones are more fun.”

“The other side, please,” Thomas said, and waited for Varvara to turn her arm. The metal bracelet that served as a tracking device stroke magic monitor remained intact, just as it had at each of his prior visits. “Thank you.”

“At least you’re polite,” Varvara said. “Go on, then, what’s the news from the other world?”

The news was that Her Majesty’s peace held. He told her about how the second-youngest of Mama Thames’s daughters was considering joint honours in Physiology and Pharmacology, and a few brave members of the first generation of Quiet People to acclimate to the sun would be matriculating with her. A whole generation of children, grown up and making their own choices about how they wanted to spend the rest of their lives. In the summer, Abigail Kamara would graduate university having read Forensic Psychology, and join the Folly as one of two new apprentices.

Varvara’s eyebrows shot up. “What on earth do you need two for?”

That was more or less what the Commissioner had said when Thomas had raised the idea with him. This time, as with that one, his answer remained the same. “The goal is to improve civilian cooperation with investigations through regular engagement, which will only occur with increased police presence among the community outside of active incidents.”

She considered him for a moment. “So basically, you need the bodies. Peter told you to say that?”

“Peter has always understood the language of modern bureaucracy, but we’ve worked together for nearly a decade. I’ve paid attention.”

Another long, searching look. “You’ve decided to end his apprenticeship, haven’t you.”

“I’ve considered the possibility,” Thomas said carefully.

“You wouldn’t agree to two new apprentices if you thought you were still going to be running around keeping any more buildings from falling on the first one. Which begs the question of why you’re being so squirrelly about it. What, are you worried he won’t need you any more?”

In the old days, the formal ending of an apprenticeship always happened the same way. For each graduating student, three Casterbrook masters would be found to speak of the apprentice’s readiness. Another three from the Folly would judge their testimony and, if the young man was deemed sufficiently prepared, grant him his mastery.

Now there was only Thomas. The demi-monde could speak to Peter’s skill in policing – and did, if their latest stakeholder meeting had been any indication. But there was only Thomas who could speak to Peter’s skill in the forms and wisdoms; only Thomas could judge what he knew of Peter Grant and call an end to the oath of apprenticeship, acknowledging Peter to be as true a practitioner as all those who came before him.

The old method was, in retrospect, a rather premature bit of self-congratulation. All that supposed knowledge, that prized education for which the school was so fêted, hadn’t done one jot to keep its students alive. But Peter – Peter had earned his mastery twice over with cleverness and determination and a streak of lionhearted courage masquerading as utter disregard for his own well-being, and the truth was that he had not needed Thomas for some time. He was owed the acknowledgement Thomas’s own masters and colleagues would never have given him, and the pickle of the thing was that Thomas simply had no idea _how to do it_.

“You Englishmen and your aversion to feelings,” Varvara said, her voice tinged with amused sympathy. “Very well, then. Have you picked your second apprentice yet?”

“The process is proving more difficult than I had originally anticipated.” There were a few promising candidates among the probationers, but competition for those candidates among the OCUs was a hair trigger away from turning into a bloodbath. Some of the other DCIs made Alexander Seawoll look positively mellow.

“You could always turn Peter loose and see what he drags back. He’s got a habit of collecting interesting strays.”

“Perhaps.” He checked his watch. It was past ten; they’d been speaking for more than an hour. “Varvara –"

“Just tell me,” she said.

“Evgenia Petrovna Kucherov,” Thomas said. “I am sorry. I’m told it was peaceful.”

Varvara was still for so long that it was as though she had frozen. When she spoke, her words were the crack of ice shearing from a glacier. “She was the one who saved –"

“I know. When I gave my condolences to her children, I informed them that there was still a favor owed, if they ever needed it.”

A breath in. Another drawn-out moment of motionlessness, and then she laughed shakily. “That melodramatic bitch always had to prove she was tougher than everybody else. Figures she’d be the last one to go.”

“The last of the practitioners like you?”

“Oh, Thomas,” Varvara said. Her eyes glittered, but when she stood up her back was tall and unbending. “None of them were like me, were they? Not at the end. If they were, they wouldn’t be dead.”

He drove back to London slowly. The weather had picked up from a drizzle to proper rain, big fat droplets striking against the Jag’s windshield; the A23, when he finally reached it, was an endless sea of brake lights. He tapped his fingers against the steering wheel, crept forward, and tapped his fingers again.

The Missing Persons unit would have had first crack at the case before deciding there was a high enough likelihood of harm to the potential victims to warrant a call to the Murder Team. The Murder Team, in turn, would have done their due diligence in actioning statements and TIEs and compiling enough information to establish a basic timeline for each victim before they had realized the matter was Falcon-related, or at least Falcon-adjacent. Peter must have spent the whole morning going through the paperwork, if he wasn’t at it still.

The museum was conveniently located right around the corner from the Folly, so rather than waste time trying to find street parking that would inevitably be farther away anyways, Thomas parked the Jag in the coach house and went upstairs – no Peter. He did find Molly typing at rapid-fire speed at the computer, though she jumped to her feet as soon as Thomas entered the room.

“My apologies for interrupting,” he said. “Has he left already?”

She nodded, tilting her hand back and forth to indicate Thomas had only barely missed him.

“Thank you. I’ll leave you to it, then.” Whatever ‘it’ was. Several Christmases ago Peter had gifted her a tablet modified with a battery-interrupt and packaged with a slim grey device that did something to the Internet, so these days she conducted most of her personal business from the comfort of the Folly – but there were times, Peter had said, when you just wanted a proper keyboard. As he swung the door of the coach house closed behind him, he could hear her take up typing again. Perhaps she was communicating with one of her electronic friends. Peter had steadfastly refused to involve himself in Molly's use of her program of choice - Kindle or Tinder or whatever it was called - but it was no secret there were six or seven of her regular correspondents with whom she exchanged cards at the holidays, mailed from addresses as close as Portsmouth and as far as New York.

He stepped inside the main house briefly to collect his galoshes and devour one of the sandwiches Molly had kept under a metal cloche, then set off for the museum. On the way there, he pulled out his phone.

“ _Hello?_ ”

“Hello, Peter. I’ll be at the museum shortly.”

“ _You’d better hurry, sir_ ,” Peter said. In the background, the buzz of other quiet conversations ebbed and swelled. “ _Because I’ve done rooms one, two, and five, so I’ve only got about ninety left to go_.”

According to the museum director, patrons of the arts, and wealthy patrons in particular, were timid creatures whose chequebooks did not need to be frightened off by the galleries closing for a police search; she wanted the trouble found, but she wanted it found _quietly_. This meant that when Thomas caught up with Peter, the younger man was trying and failing to pass a group of tourists clustered in front of the Rosetta stone. He looked as though he was half a minute or one trod-on foot away from pulling out his warrant card and arresting them on the spot. 

Thomas called his name, and Peter’s eyes snapped to him, raising a hand in acknowledgement before he started trying to wade back through the crowd. Thomas inclined his head at the exit to the main atrium. There was a comparatively quiet corner by the lifts where they could formulate a plan.

Away from the crush of people, the tension in Peter’s frame took on a subtly different shape: not irritation, Thomas realized, but frustration.

Although he suspected he could guess the answer, he asked, “Have you found anything?”

“Nothing yet,” Peter said. “I mean, there’s tons of _vestigia_ , but that’s the museum being, well, a museum. Nothing that makes me want to hop the next train to Knaresborough without so much as a note goodbye.”

“An unfortunate hazard of our location,” Thomas acknowledged, “but not an unanticipated one. Was there anything notable in the files?”

“Not that they all had in common,” Peter said. “Different ages, different races, no overlap in what they did or where they lived. Two of our victims – Davies and Wheeler – didn’t have any close family. Okore’s got an adult daughter working up in Edinburgh. Davies and Okore both immigrated here, but Davies came as a kid with his parents and Okore came for uni, and they didn’t arrive the same year or anything.”

“It is possible that whatever happened to them was simply a matter of being in the wrong place at the wrong time,” Thomas pointed out.

“Yeah,” Peter said, that single syllable rife with a scientist’s distaste for explaining why anything happened with ‘it just did’. “The weird thing is, it didn’t look like a practitioner’s work,” he added, running a hand over his shorn hair like a more satisfactory explanation might fall out of it. “I watched the tape three or four times, but none of them had that fixated look of someone who’s been, you know –" He wiggled his fingers.

“Encouraged to act in a way contrary to their free will?” Thomas said. “I may want to examine the video myself later, but I trust your assessment is accurate. What _did_ they look like, then?”

Peter thought for a moment. “Wheeler looked a little confused, Davies was maybe a bit worried. Okore looked happy.”

Odd, but it didn’t rule out the possibility of a non-Newtonian glamour, especially if one of the more powerful members of the demi-monde was involved. “Security cameras?”

“Show them leaving the station in the same direction, but nothing else. Most of what’s around the station is residential. Everything that isn’t doesn’t keep video for longer than about 48 hours, if they’ve got cameras at all. It’s Knaresborough, sir,” he added long-sufferingly, as though that was sufficient explanation. Perhaps it was.

“Well, let’s see if we can’t run down something more helpful. If you continue on this floor, I’ll start upstairs and work my way down,” Thomas said. “Check in on the quarter hour, and keep your staff handy.”

Peter patted his jacket. As it had become increasingly apparent that a staff might make the difference in Peter surviving his next encounter with ethically challenged practitioners - and that there were several of those running around - they’d had a devil of a time coming up with a design that he could carry without looking, as Peter had said, “Like a right posh wanker. Not that I think you look like a wanker, sir.”

“Astonishingly, your opinion of my appearance is not my primary concern,” Thomas had said dryly.

The reality was that there was simply no easy way to conceal an object with a three-foot core of folded steel on one’s person without making it uncomfortable, inaccessible, or both. Peter had asked why they couldn’t cut the core shorter, but Thomas had explained that to do so would truncate the welded matrix that actually made the staff useful in the first place.

“Okay,” he’d said. “So what if we keep it in proportion, only smaller?”

Thomas had been doubtful. The Sons of Weyland had always made staves in the same size, and he was far from a master blacksmith himself. “It would take a great deal of precision in the welding. Even with two pairs of hands it would likely require several attempts. Perhaps if we consider an alternative exterior –"

“I know we keep hoping the elitist bastard will underestimate me again, but I’d rather not stake my life on it, sir,” Peter had said, and Thomas, who had sworn to himself that he would not lose another apprentice to Martin Chorley, had stopped arguing, rolled up his sleeves, and done his best.

The end product was, he had to admit, a fine piece of work. The shell of the staff had been designed to look like a friction-lock baton at full extension, thin enough that it could be concealed in the line of a jacket or coat but long enough to hold the miniaturized staff core. Molly had sewn elastic bands with grip-strips of rubber along the left-hand seam of each of Peter’s jackets to hold it in place. She had then made Peter run up and down the stairs in every single one. In theory, this was to test that the staff wouldn’t fall out in the middle of a pursuit. In practice, Thomas suspected, it was because he’d failed to clean his plate at dinner the previous evening.

And if ultimately Peter had been right about Chorley, it was not in the way either of them had anticipated. Chorley failed because he saw the staff as the weapon of a practitioner. It was a mistake on two counts; first, he had never thought of Peter as being a true practitioner. The second and more crucial of his mistakes was this: Peter’s staff was the weapon of a policeman, too, and Peter himself was as fine at one as he was the other.

The autopsy report on Martin Chorley, AKA the Faceless Man, listed his cause of death as a fatal brain haemorrhage brought on by severe neurological degradation. It went on to list that along with minor cuts and bruises, Mr. Chorley additionally suffered a fractured femur and ruptured testicle due to being repeatedly struck with a police baton while resisting arrest. The injuries, the coroner noted, had not been fatal.

Chorley’s arrogance, on the other hand, had been. An object lesson in the dangers of overconfidence.

Thomas hefted his own staff and gave Peter a nod. “Good. Let’s begin.”

The upper floor of the museum was arranged in a loop around open space, with the ceilings of the main atrium reaching all the way up to the top of the building. Ascending the north stairs, he started with the galleries on Japan and the special exhibitions on the upper levels, then descended to the main level of the floor to start working through Ancients Egypt, Greek, and Rome. These rooms were less popular than their counterparts on the ground floor, though he still found himself dodging the odd school group. More importantly, while fascinating in their own right, the artifacts he passed carried only the _vestigia_ of the mundane, of the long-dead owners who had once imbued these items with meaning and of the passing crowds who had given that meaning new life after so many years.

Peter called at the end of that first long passageway. Although there was apparently a Greek vase that looked remarkably like the one sitting on a pedestal in the Folly’s mundane library, he hadn’t noticed anything out of the ordinary yet. Thomas confirmed that his search had similarly yielded no results, then moved on to Europe. Rather than begin with the oldest artifacts and proceed in chronological order, these rooms began with the medieval period. Towards the exterior of the building they progressed forwards into the modern era; moving farther in, they regressed back to the ancient.

There was something unsettling about walking through the exhibit on his own lifetime. The art pieces might have been displayed in his parents' home. He might have sat at a table like the one on display; he might have sipped tea from that porcelain. The British Museum had opened more than two centuries ago, when Thomas’s many-times great-grandfather might have been a patron. Yet in another two hundred years, it would not be Thomas’s own descendants visiting these halls, but Thomas himself, caught in stasis while the world lived and died and grew older around him. Peter’s beloved, baffling technology would one day join the artifacts from Thomas’s own childhood. How many people in that distant future would see them as anything other than remnants of a bygone time, gathering dust in glass cases?

He was nearly at the end of the upstairs galleries when he found their target. It wasn’t _vestigia_. It wasn’t like anything he had ever encountered before. The only way he could think to describe it was as the echo of a song, but that was woefully inadequate. A song began and ended; it could be started from the middle and stopped just as abruptly. Whatever had left its mark on the artifact before him simply….was. It had existed before the first stars were birthed from the darkness and would go on existing after the last of them had died.

He stepped closer to the display case. Underneath the song was something else, something -

The first thing he noticed was the screaming, high-pitched and terrified until it cut off with a wet crunch. Following on its heels was the smell of moss and blood and damp earth – and that same song, woven through the _vestigium_ like an odd-colored thread. _Come to me_ , it called. _In water, you shall be consumed; in stone, you shall be saved. Come to me. Be consumed, and be saved._

Thomas opened his eyes.

The woman was lying in a foetal curl under the glass. The metal plaque on the base was labeled: _Human female body, aged approximately 20 years at death. Found preserved in a bog. Hair and skin well-preserved. Fragments of limestone in skull. 24 BC – AD 108 (circa); Yorkshire Dales National Park._

In his pocket, his cellular phone buzzed. Peter, no doubt calling for his check-in.

“Room fifty,” Thomas said. The song lingered in his skull like a promise, a threat, a landmine under loose earth. He didn’t want to know what would happen if he triggered it. “It’s here.”

Peter must have bolted for the stairs and damn the tourists, because he appeared next to Thomas less than a minute later. His breathing was faster than normal, but controlled. “The mummy?”

“The bog body, if we’re being specific. I suspect that when we inquire, we shall find she was added to the museum’s display five weeks ago.”

Peter leaned in close towards the glass and winced. “Ow.”

“Indeed. However, while the _vestigium_ is remarkably clear given its age, I believe we ought to be much more concerned about the effects of that music.”

Peter’s expression said several words that were impolite to repeat in mixed company. What actually came out of his mouth was, “What music, sir?”

Thomas glanced at him. “You don’t hear it?” It had been the first thing he’d noticed, and even if Peter couldn’t pick it up off the body, he ought to have heard it in the _vestigium_.

Peter closed his eyes, concentrating. After a moment, he frowned and reopened them. “I can tell something is there, but it’s like – like whatever it is, it doesn’t want me to know about it. Like it’s not meant for me.”

“Suggesting the effect is targeted after all,” Thomas said. “I don’t believe it’s inherent to the corpse, but judging by its presence in the _vestigium_ , this woman was exposed to the source of it prior to her death.”

“You're saying she’s a carrier. What’s she carrying?”

“The promise of salvation,” Thomas said.

“Let me guess,” Peter said. “It involves dying in a horrible manner.”

When did it not? “Most likely. The song mentioned water and stone.”

Peter frowned, pulling out his phone. “Hang on – tell me what it said, exactly.” Thomas told him, and Peter tapped at the screen for a few seconds. "I know it's here somewhere...ha." He looked up in triumph and held the phone out. “I know where our missing people have gone.”

“The petrifying well,” Thomas read.

“Consumed by water, saved by stone,” Peter said. “And Knaresborough’s famous for a spring with water that preserves things in stone.”

“It seems unlikely to be a coincidence,” Thomas agreed.

“The _genius loci_ of the well?”

“If there is one, it would gain no benefit from luring people to their deaths. Nor does it feel like their particular brand of glamour.”

“Yeah," Peter said. "So then what’s down there?”

“A valid question,” Thomas said. “A few possibilities come to mind –" none of them good “- but I won’t be able to say with certainty until I’ve had the opportunity to do some research. In the meantime –"

“I'll follow up on the mummy,” Peter finished. “By the way, sir, fair warning: if you try to run off to North Yorkshire I absolutely will not hesitate to call in the big guns.”

Thomas ran the numbers through his head. Peter was quick and brave, but he fought like a copper – to disarm and disable. Thomas, under a compulsion, would fight to kill. Forewarned, there was only one person fast enough to have a chance at stopping him. “Molly?”

“Molly,” Peter confirmed. “Seriously, though, you’re not experiencing any particular longing for the north?”

Thomas examined the snarl of emotion in his chest. He felt – but no, “No more than usual. Which is to say, not at all.” Not for the north. Not for anything so easily attained.

“Thank god,” Peter said, laughter returning to his eyes. “I’d have done it for your own good, sir, but it wouldn’t have been pretty.”

_In water, be stone. Be consumed, and be saved._

If only salvation were so simple.

Before they could leave, however, they had to supervise the removal of the corpse to a basement storage and preservation facility. Thomas thought of Abdul’s complaints about sample contamination and did his best to channel irate Scottish gastroenterologist: “Do you have a quarantine protocol for items in the collection? No? Then there should be minimum contact with the body until you hear from Sergeant Grant or myself, and the only people who should be in the same room should be those who have handled it before.”

“The gala –“ the curator started.

“Is perfectly safe,” Peter said, offering the man his most charming ‘I’m a policeman, trust me’ smile. The curator fidgeted, but didn’t protest further. “We’ve established that the radius of the effect around the body is less than three metres. I wouldn’t bring your guests into the same room, but if you follow my governor’s instructions there’s absolutely no risk.”

They left after providing him with both of their cell phone numbers, the number for the Folly’s main line, and strict instructions to call immediately if anything changed.

“What’re the odds that if something does happen, they won’t call until after the gala’s over so that there’s no chance of us gate-crashing with a full tactical team?” Peter asked as they made their way down the museum’s main steps.

“I refuse to speculate on an active case,” Thomas said. “But if I did, I would put them at at least eighty percent.”

“Yeah,” Peter sighed. “If not higher. Even Lady Ty’s more cooperative these days.”

She was more cooperative, Thomas knew, because in the weeks preceding the operation that finally took down Martin Chorley, Peter and Beverley had had a series of quiet rows that had led to a surprisingly amicable break-up. Thomas and Molly had traded watch over him for a few weeks, but there was a resigned quality to his heartbreak, like he had made his decision and steeled himself against the consequences. “She’d’ve waited until I was ready to leave the Folly,” he’d mumbled when Sahra had brought him back staggering from the traditional post-break-up drowning of sorrows. “But I don’t – I don’t think I want to leave.” When he fought past the duvet to grab Thomas’s arm his grip was like iron, even though he couldn’t hold his head upright without it lolling to one side. “Is that – it’s okay, right? It’s okay if I stay?”

Thomas had covered his fingers with his own hand and said, as firmly as he could, “Peter. The Folly is your home for the rest of your life. No matter with whom you choose to spend it.”

“Oh, good,” Peter had muttered, and promptly fallen asleep with his fingers still knotted in Thomas’s sleeve.

And then Peter had nearly died, and Thomas had nearly died, and Martin Chorley did, in fact, actually die, and by the time the dust had settled nobody particularly cared to revisit whether the Brook/Grant break-up ought to lead to awkwardness between the Folly and the demi-monde. Beverley had kissed Peter on the cheek and punched him in the shoulder when he got out of hospital, in that order, so presumably all was forgiven. Peter had never said otherwise, and Thomas had never asked.

As for Cecelia Tyburn McAllister-Thames, however: "I'm not sure we ought to mistake a lack of active antagonism for cooperation," he said.

"If she's not trying to kill me, I'm happy," Peter said.

Molly was waiting to collect their coats and umbrellas when they walked into the house. As soon as he had relinquished his wet things, Peter said, “Nightingale got whammied at the museum by whatever’s making people vanish, so if he tries to leave and I’m not there, just, you know. Tackle him or something. Gently.”

The aluminum umbrella frames creaked as Molly clutched them to her chest. Thomas stared at them both in betrayal. “I beg your pardon.”

Peter shrugged. “Better safe than sorry, sir.”

Judging by the ferocious expression on Molly's face, Thomas was quite certain that she was already planning how to barricade the exits. “I am perfectly safe,” he said.

“And now you’ll be even safer,” Peter said peaceably. “I’ve got to go to the coach house to make some follow-up calls.”

“Traitor,” Thomas muttered, and Peter threw him a grin as he slipped away out the back door.

With no other options remaining to him, Thomas settled himself in the library under Molly’s unblinking gaze. After Chorley, one of Peter’s projects had been the organization and cross-referencing of notes from county practitioners going back to the founding of the Folly. It had been a painful process. They had spent hours hunched over the desks, recording page numbers, puzzling through how to categorize different types of incidents, and arguing about threat ratings until they had, at last, a complete index of every documented magical event involving a Folly practitioner that was searchable by the event’s region of occurrence, nature, and urgency of required response.

There were fifty-three recorded incidents of individuals going missing that had occurred in North Yorkshire. Of these, eight had occurred due to a rogue human practitioner and could be discarded as irrelevant. Another nineteen were the aftermath of fae bargains gone poorly, and equally unlikely to be of use. This left twenty-six possibilities remaining. Thomas pulled the first notebook closer and began to read.

_Kelpie responsible for the drowning of three young men aged 20-27 identified and dispatched May 15th, 1793…_

_Winter solstice led to increased intangibility between worlds; Mrs. Brockthwaite fell through and could not be retrieved despite my best efforts…_

The pile of discarded journals grew. A pot of tea appeared on a tray with sandwiches, but he paid it no heed. The occurrences in these notes were tragedies, certainly, but they were the ordinary tragedies of an extraordinary world.

_Reginald has sent a telegram requesting assistance in the matter of the trees he believes are swallowing people whole. I leave for Settle in the morning…_

_Mr. Edward Morton’s bones located, destroyed, and sent to the sea for dispersal. I have informed the Wickham lad’s parents that it is unlikely we shall ever find his body…_

_My predecessor in this position had disappeared the day before I arrived. We found him today halfway across the moors, making his way towards a cavern he claims holds a great and terrible deity capable of granting eternal life. He is clearly raving, and yet he seems utterly convinced of his own sanity…_

Thomas's fingers spread over the page, pressing it flat as though he might need to keep the scrawled cursive from changing shape.

_We have taken him by train to Meadowfield Asylum. I fear there is little that can be done. He has named his goddess the Lady of the Lake, as if he is Merlin seeking Excalibur. She has promised him salvation, he says. The doctors say it is shell shock, and I believe them. Archie was injured by the War in more ways than one…_

_I have learned that Archie is not the first to be found in such a state. Four others have been discovered crossing the moors from the surrounding villages; three more have vanished entirely, and left only their tracks. All have claimed the cavern as their destination…_

_Joined today by Masters Reginald Martin and Donald Freeman from London. We set off for the cavern to kill the creature inside it, and hope to so free the poor souls it has ensnared from their madness…_

_It was a mistake, it was a mistake, it was a mistake. Donald is dead. Reginald is dead. As soon as we caught a glimpse of the creature in the pool they threw themselves from the path; I heard their bodies hit the water. I shall never forget the sound of it, nor the look on their faces as they flung themselves to their deaths. They were smiling. I could feel the beast call them and was helpless to prevent it. I have informed the Folly, and they have said I am as mad as poor Archie. They may be right. I no longer feel fit to practice the forms and wisdoms. I no longer feel fit for much of anything. It is a monster, and for all our magic we are as ants before it._

Clipped behind the page was a sheet of yellowed paper. He slid it free. It was a letter from the Master of the Folly to the family of one Oliver Sachs, Esq., regretfully explaining that he had begun to suffer from hallucinations and been sent to Meadowfield, where he had taken ill and passed away.

Carefully, Thomas replaced the letter and closed the journal. The Folly had refused to believe there was no power greater than their own, and they had been wrong. Over the last century, how many had died in the moors for that error?

His breathing was steady; his hands hung loose at his sides. His mind had narrowed to an all-encompassing fury, to white-hot steel in the moment before the hammer strike.

How many had died in Ettersberg for it?

He stood. Molly hovered in the doorway, and it was only years of long practice that gave him the composure to nod at her in a reassuring manner. But instead of moving out of the way, she hesitated. Her expression rippled with poorly hidden calculation. She was, he realized, trying to determine whether she needed to stop him.

He was worrying her. The embarrassment hit him like a bucket of cold water to the heated metal of his temper, cooling it instantly. “I’m going to the coach house to speak with Peter. Why don’t you accompany me?” he said. “I’m sure he would appreciate the sandwiches.” She nodded eagerly, and he didn't think he was imagining the relief in her eyes as she followed him out of the room.

As it turned out, however, she didn’t need to accompany him very far. They ran into Peter as they were descending the stairs. Rain had beaded on the shoulders of his jacket and at the tips of his eyelashes, which dipped up and down in rapid, unsettled blinks. Molly took one look at him and shooed them both into the kitchen. In seconds, a fresh kettle of water was heating on the stove. Toby whuffled and kicked in his sleep, undisturbed by their arrival. His hearing was no longer what it used to be and all the brown of his muzzle had long gone grey, but he chased imaginary rabbits with the same vigour as always. It was all terribly normal, and yet the normality of it felt unnatural in the face of what Thomas now knew.

When the tea was ready, Peter accepted the cup Molly poured for him and wrapped his fingers around the china. Thomas could hear him breathing, slow and purposeful. He didn't drink.

“Tell me,” Thomas said, and he did.

As she had explained it to Peter when he’d called her, Claire Ranganathan wasn’t sure when exactly she’d found the body in the bog. This was on account of her having her brand new iPhone in her jeans pocket when she went into the bog herself, depriving her both of a thousand quid investment and of any reliable method of telling time - Peter’s words, not his. Given how frequently even the non-wizards of Thomas’s acquaintance seemed to complain about dropped calls, broken casings, and insufficient data to do whatever it was cell phones needed data for, ‘reliable’ seemed a bit of a stretch.

Thankfully Ms. Ranganathan hadn’t gotten too far from the well-trod trails of Ingleborough, the local mountain stroke tourist trap. “Featuring,” Peter muttered, swirling the cup in circles, “grass, dirt, and what’s left of an Iron Age hill fort, because for some bizarre reason the Romans were mucking about in Yorkshire when they could have been enjoying the Italian sun.”

Ms. Ranganathan certainly wasn’t up to appreciating the scenery at that particular moment in time. Absent a functioning phone, she had to rely on the assets remaining to her: namely, a good pair of lungs. A few minutes of brisk shrieking got her assistance in the form of Graeme and Jamie Murray, two holidaying Americans who were able to extricate her far enough to see something else rise out of the mud with her, give a good shriek themselves, and drop her right back in it. Which then made Claire shriek, and by that point someone a little further up the path was already dialing the ranger service. Three-toned screaming, Thomas was informed, not being one of the charming natural features of the Dales. No matter how shaken he was, nothing could take away Peter’s cheek for long.

Witness statements were notoriously unreliable, but the wonder of modern technology was such that Peter was able to report a Ranger Hollingsworth arrived in her Land Rover at precisely thirty-two minutes past ten to find three mud-spattered people at the edge of the path. She also found half of a mummified hand emerging from what had, up until approximately fifteen minutes previously, been a rather unremarkable bit of bog. Hollingsworth’s first call was to the Area Manager to come collect her trio of tourists; duty to the public discharged, she then began to follow park procedure for the discovery of human remains in a peat bog.

Peter grimaced. “Have I mentioned how much I hate the countryside?”

“Park procedure,” Thomas said.

Park procedure was for the body to be removed and catalogued by a contract archaeology team under supervision from one of the rangers. “And that’s when we get to the really weird bollocks,” Peter said. “Because I talked to Ned Hoffman, the guy in charge of the contract team, and he said they nearly fired three lab workers because the results kept indicating –“ His voice faltered. “Living cells.”

Thomas had little need for biology, but after countless lectures from Abdul about his own cellular peculiarities, he understood enough to make sense of what Peter was saying. Suddenly the cause of his discomfort came into awful focus. “She’s alive?”

“Well, she’s not _dead_ ,” Peter said tersely.

“I’m afraid that may not be the worst of it.” Thomas passed him Oliver Sachs’s last journal. Peter skimmed through it, his complexion going sallow as he read.

“What –”

“In his _Compendium Monstra,_ Halstone calls them _pseudo deorum_. Creatures so huge, so powerful, so ancient, as to be functional gods. The Folly never took his work all that seriously, but he had several accounts of practitioners who had encountered them.”

Incredibly, a flicker of irritation crossed Peter’s face. “Fuck me, Lovecraft was right? Sorry, sir,” he added. “I'm not keen on him. He was kind of a racist bastard in addition to being a noted tentacle-fancier and writer of stories about giant eldritch cephalopods that were going to rise from the sea and bring about the end of days.”

“Halstone doesn’t specify tentacles,” Thomas said. “But I believe the _pseudo deorum_ may still be closer to these monsters you're describing than to, for instance, Father and Mama Thames. The _genii locorum_ are tied to the existence of the sites which gave them their powers. Though they call themselves gods and goddesses, they can be killed.”

Peter swallowed with effort. “You’re saying this thing can’t be.”

“There is no record of it ever being done. That does not mean it’s impossible to stop it, only very, very difficult.”

Peter Grant had tracked down a ghost in Covent Garden because the Job had demanded it. He had given himself to a fae queen because it was what needed to be done. He had risked his life in situations both magical and mundane, over and over, because Peter didn’t make oaths he didn’t intend to keep.

“We’re going to try anyways, aren't we,” he said. It wasn’t a question.

“Yes,” Thomas said. “We are.”

He made the necessary arrangements in the hours remaining to him. Mama and Father Thames would keep the peace in the demi-monde for their own sake if no one else's; Abdul and Harold Postmartin would help coordinate Abigail's training with Lady Caroline. Elsewhere in London he knew Peter was doing the same, calling on his parents, reaching out to Sahra and Beverley before returning to the Folly for a late dinner. Neither of them could muster much of an appetite for it.

That night, Thomas dreamt of a pool in a cavern. Underneath the water, something writhed in slow undulations, appendages appearing and disappearing like the foaming crest of a wave. One looked like a human arm. Another, the scaled claw of a lizard. Others were barely even recognizable as flesh, misshapen and unnatural and always moving, breaking through the water without disturbing the mirror stillness of its surface. The creature was dreaming too, Thomas realized, and as it dreamed it sank deeper and deeper into the earth, its song resonating through the cavern instead of reaching across the land.

_Come to me. In water, you shall be consumed; in stone, you shall be saved. Come to me. Be consumed, and be saved._

He dreamt of other things that night, but when he woke the next morning, all he remembered was the song.

They assembled in the coach house: Thomas, Peter, and Molly, with a disgruntled Toby in her arms. It had been like this before they went to deal with Chorley, too, but then he had needed to make sure she knew that there were people who would take her in if the Met had no use for her, as much for his own peace of mind as for hers.

He didn’t feel that way now. “Thank you, Molly,” he said, and held out his hand. She shook it, only trembling a little, and turned to Peter, who looked at her and said, “Oh, hell.” Then he hugged her, dog and all, arms tightening for the briefest moment before he stepped back and stuck his hands in his pockets.

“We’ll call,” he said. Molly nodded, her clenched fists twisting wrinkles into the fabric of her apron.

The three hour journey from Euston station to Knaresborough felt much longer. They had picked up a canvas carrying case from the museum on their way to the station, and it sat at their feet as a grim reminder of the task ahead. Peter did his best to lift the silence, but as the hours wore on he grew quieter and quieter. He hardly spoke at all when they reached their destination and disembarked, only consulting his phone once to orient them in the right direction.

The cave was on the edge of town, across the River Nidd. They had arrived at mid-morning, too late for working commuters and too early for meandering tourists. There might have been no one else in the world but the two of them, and as they stood before the yawning maw of the cavern, Thomas felt himself a ship struck by lightning. A spark of adrenaline raced down his spine, setting him ablaze – and when the rush of nerves passed through him, cool certainty was waiting, easy as slipping below the water. There was a fight to be had here. The slim chance of success did not detract from the necessity of it.

Beside him, Peter looked grim. “We’ll stop it, sir,” he said. The baton he carried, welling over with power, remained perfectly still in his hand without a tremble to betray him. Had there been any other people around, none of them would have noticed how scared he was.

Other people didn’t always notice much about Peter beyond what they wanted to see. But then, other people hadn’t served with him for nearly ten years. Other people hadn’t sworn an oath to guide him and protect him. Peter said, “We’ll stop it,” like he was trying to convince himself it was the truth, and although he didn’t add, _won’t we_?, hesitation lay in his eyes like a shadow.

It was a small reprieve. If Peter didn’t ask for reassurance, then Thomas wouldn’t have to discover if he could make himself provide it. Peter would see this through regardless, and Thomas would not have to face what waited in that cave knowing some of the final words exchanged between them were lies: _we’ll stop it. We will_.

“I suppose we could leave it for the Knaresborough police, but I don’t think they’d take too kindly to that,” Thomas said, and felt himself smile at the startled huff of laughter dragged from Peter’s throat.

“Probably not.”

“It will have to be us, then,” Thomas said, and let a werelight bloom in his free hand as he led them down into the darkness.

They descended. Water dripped in oily gleams from the ceiling and down the walls. In the illumination of the werelight Thomas could see the stone was smoothly rippled and streaked with color from the passage of the water.

“Behold the amazing petrifying well,” Peter said, and then a minute later, “People actually pay to see this, you know, which is clearly the more amazing thing.”

“Is that what happened to her?” Thomas asked, nodding over his shoulder at the canvas bag Peter had slung across his back. 

“No,” Peter said after a moment. “It’s not. What the well does, it’s not true petrification.” His voice grew steadier as he was caught up in the explanation. But that was Peter; knowing the _why_ , Thomas had learned long ago, mattered as much to him as the _what_ and _how_. “The water is high in minerals, so when it evaporates off a surface, it leaves behind a coating of those minerals. The more water evaporates, the more layers of minerals build up. In real petrification, organic material is actually being replaced, not just covered.”

“And our nameless friend?”

“I _knew_ you weren’t listening on the train,” Peter said.

“I fail to see how the architectural qualities of peat have any relevance to our investigation,” Thomas said. “The mummy, Peter.”

“You remember I talked to the guy in charge of the archaeology team.”

As the path dropped away before his feet, Thomas threw another werelight up, bright enough to see that they had approached a crudely carved staircase. “Watch your step. And?”

“I got the impression he was simplifying the process a bit for us uneducated coppers, but…He said it was like pickling food, with the high acidity and the cold doing most of the work of preservation, and the layers of peat maintaining it by preventing any exposure to airborne bacteria.”

Thomas thought, awfully, of the cellar in the Folly where Molly made and kept preserves. It was by far the coolest part of the house, but it had nothing on the temperature in the cave. Their breath fogged in the air. Even in sheepskin gloves, his fingers were beginning to lose sensation.

“Sir,” Peter said.

He’d stopped on the first stair without realizing. The song was so much louder here, so much stronger. It was the hymn at Hugh Oswald’s funeral; it was the tattoo of marching drums; it was a lullaby from a thousand mouths, promising what he could never have.

Something gripped his wrist. Peter.

“I’m fine,” Thomas said.

“If it’s all the same to you, sir, I’d rather not watch you dive like a lemming off a cliff,” Peter said, and didn't let go.

They kept walking. At the bottom of the stairs the well opened into a large chamber, the center of which continued spiraling downwards. There was no movement in the air anymore. At the lip of the cave shaft, the darkness seemed to be as endless as the song echoing through it. Peter readjusted his hold on Thomas’s arm. “Onwards?”

The song filled his head. He thought of Varvara, grieving for her lost friends, and of Molly, expanding her world to span oceans. He thought of Alexander Seawoll, begrudgingly accepting a promotion to Superintendent so that Miriam Stephanopoulos could take his position as SIO of the Belgravia murder team; of Abdul, training a replacement so that Thomas wouldn’t have to do without assistance when he retired; of Lesley May, who had always believed Thomas could have done better. He was so _tired_. “No.”

The pressure around his wrist increased slightly. “No?”

He thought of Peter. Peter, whose magic had the same roundabout cleverness as his mind, that sharp, surprising power that split the air like the sound of a trumpet – or the blast of a copper’s whistle. Peter, to whom Thomas owed an oath and more. Peter, who would grow old as Thomas had, and never grow younger again. 

The song hadn’t called him, and for all of the failures that could be laid at Thomas’s feet, Peter Grant would not be one of them.

“No,” he said. “I will continue on alone. You have kept your oaths to our soverign Queen and to the fellowship we share. You have fulfilled the terms of your apprenticeshood, and it has been an honour to serve as your teacher and senior officer these past ten years.”

“Sir –”

“Everything I have done,” Thomas said, “was better for your being there. The Folly was better – will be better, with you at its head.”

“Sir!”

“I, Thomas Nightingale, do hereby invest in you, Peter Grant, the full rights and responsibilities of a master of our fellowship. Keep your oaths to your Sovereign, your fellowship, and the peoples of this nation –”

Peter let go of his wrist and punched him in the face. Pain exploded across his cheekbone; he staggered back a step. “Sir,” Peter said, breathing hard. “With all due respect? Shut up.”

“It shouldn’t claim the both of us,” Thomas said. The pain in his cheek condensed into a warm throb. He needed to make Peter see - he needed to make Peter _understand_ -

“It’s both or neither,” Peter snapped, and then he grabbed Thomas by the lapels and kissed him.

“Oh,” Thomas said, when he finally let go. He had needed to do a great deal of kissing back first. The throbbing sensation appeared to have inexplicably migrated across his whole face.

“Um,” Peter said. In better light, he might have been blushing.

“Were you waiting for the end of your apprenticeship,” Thomas heard himself ask, “or was this because you think we’re about to die?”

Peter blinked. “Are you – if I was going to kiss you every time I thought we were about to die, we’d have been doing that for ages.”

“Oh,” Thomas said again. “Really?”

“I admit that most of those times might have been my own fault,” Peter said.

“As long as we’re in agreement,” Thomas said. “Are you sure that I can't convince you to leave?" 

“Yes,” Peter said. He was still holding the front of Thomas's coat.

"Then perhaps," Thomas said "we can start as we mean to go on." He held out his hand. Peter took it, and together, they continued down.

There were two more chambers as they descended, each larger than the last. The werelight held steady, but it cast light on less and less of each chamber. The stone stairs lost their definition and became a narrow path, and then even that lost its shape, until they had to release their grasp on each other to cling to the wall and pick their way downwards. 

They found the pool in the fourth chamber. It stretched away into the darkness, immense and immeasurable. There was no way to go forward except to go into the water. The song filled the space entirely, as though the fabric of the universe had been woven of water and stone.

And there, in the space between the threads –

The soles of his shoes splashed gently as he stepped down from the wall. Something brushed across his shoulder, but it was insignificant. _Come to me_.

_A warrior lying on a boat, the three gold crowns of his shield still bright against the dirt and blood soaking his tunic. Slumbering in the rocking embrace of the water; at peace, at last._

He took another step. The water rose to his ankles. _In water, you shall be consumed; in stone, you shall be saved._

_That same shore, tens or hundreds of years later, an old man who was suddenly growing younger and younger until he fell to his knees and was older than he’d been before, begging the Lady to grant him rest._

In another stride, it reached halfway up to his knees. _Come to me_.

_A great skeletal white horse, stumbling across the countryside until it finally toppled with a sigh, sinking into the grass until all that remained was the dust of its bones and the memory of the place it had once guarded. A wandering fae lord, his home and lands lost to battle, turning his face up to the rain until he was nothing but stone; his remaining knights, loyal to the last, waiting for the stone to take them too. A young woman, struck a killing blow that did not kill and left to slowly suffocate under the earth, and when the Lady sang to her she went gladly._

He was submerged up to the waist, but moving was as easy as walking on land. _Be consumed, and be saved._

_Three people with poison in their brain, their lungs, their spine, feeling it eat away at them in wasting inches, hearing a song and following it home._

The water was up to his ribs now. The stone floor of the pool fell away in front of him; another step and he would go under. _Come to me_.

Thomas stepped forward – and his foot hit something solid.

 _Come to me_.

He took another step. His head remained above the water. As if from a great distance, a shrill whistle cut through the song.

The walls of the cavern were shaking. No – not shaking. They were being torn apart, stone by stone.

And stone by stone, Peter was building new ground beneath Thomas’s feet.

He turned. Peter stood at the edge of the water with his staff held high and an expression of fierce concentration on his face. “Don’t you dare,” he said. “ _Don’t you dare_.”

In the silence, there was clarity. It was not a compulsion. It never had been. It had only ever been a choice, and the choice had always been Thomas’s.

He put his hand on the surface and thought, _no._

The water stilled.

“Sir?”

“It’s okay, Peter. Stay there, I’m coming back.” The water retreated from him as he walked. “Give me the bag.”

“Not if you’re going to go back out there,” Peter said.

Thomas shook his head. “It doesn't want to kill people. I believe it is attempting to - help, in a way. I think, when we return to London, we will find that all three of our victims were dying of incurable diseases. It offered them an alternative; for better or worse, they chose to take it."

"And you?" Peter said. 'You thought -"

"I've made my decision," Thomas said. Someday, they would have to talk about it. "It will respect that. Once we return this young woman and seal off the lower levels of the cavern, I don’t believe there will be any more disappearances.”

Peter looked unconvinced, but he didn't protest when Thomas took the canvas bag and unzipped it. When he lifted the body the _vestigium_ spiked and faded; as he set the woman into the water, three dark shapes snaked towards him and drew her away.

Hands wrapped around his arms, pulling him out of the water with a grip tight enough to bruise. Thomas turned into it and stepped closer, his own hands settling on the solid ground of Peter's shoulders.

“That one,” Peter said, “was definitely your fault.”

Thomas laughed, unsteady. He didn't want to let go. After a moment, Peter's hand slid down his arm until their fingers met, and hand in hand, they began the long climb back upwards.

The cavern still sang to him, cold and quiet and peaceful. It sounded like the snow falling in a German forest, like men marching towards eternity in voiceless rows down the walls of an abandoned school.

Those men existed, frozen and precious, only in Thomas' memories. They had found solace of the most permanent kind, and for a flickering moment the lure of that promised peace nearly drove him back into the darkness. As they reached the top of the final set of stairs, he hesitated.

But there was Peter, and a life still to be lived waiting for him outside the cave. The world would keep moving forward. Thomas would too.

And if one day he chose to return – the Lady would be there to welcome him.

Ahead of him, Peter made a triumphant noise at his cell phone. “We can be home by supper if we catch the next train,” he called.

 _Home_ , Thomas thought. Yes.

He raised his head and walked towards the daylight.


End file.
